This invention relates generally to the testing of wire harnesses, and more particularly, it concerns a novel modular interface adapter system used to intercouple a universal interface module associated with a test system, and a group of wire harness mating connectors.
Continuity testers are used to verify that manufactured wire harnesses meet designed electrical specifications. Continuity testers are also used in assembly processes to provide assembly information verifying that the harness is being assembled correctly. If an error is made, the assembler is immediately notified, allowing error correction before continuing. This eliminates the cost of rework, and also reduces training time. However, before a continuity tester can be used, it must be connected to the harness and programmed with a wire list. If the tester is used in the assembly process, it must be further programmed with the assembly information. The process of connecting the tester to the wire harness, and the programming of the tester, represent a substantial investment in time and money, often exceeding (over a period of time) the cost of the tester. This investment prevents many manufacturers from installing testers, especially for small production quantities or sums.
An acceptable, usable interconnect provides mating connectors to the wire harness being tested. The interconnect wiring has mating connectors to connect to the harness under test on one end, and connectors that plug into the tester on the other end. The interconnect electrically connects the harness under test to the tester. In test applications, a fixture is sometimes required to physically hold the harness while the harness connectors are plugged into the mating connectors in the interconnect. The fixture is usually built to conform to the physical layout of the harness. In assembly applications a fixture is required to hold the connectors during soldering, crimping, etc., and to show the routing path of the wires as they are laid in place. This requires a custom built, one-of-a-kind fixture for each type of harness to be manufactured. Since the fixtures are custom built, their costs are high.
Before testing can be performed, the equipment must be programmed with the wire list. The wire list specifies the electrical placement of the ends of the wires in the wire harness (normally a specific pin in a connector). For build applications, the wire list is normally arranged in the order that the harness will be assembled. For test applications, the wire list order is not important. Most test equipment can electrically scan the wiring harness and determine the wire list by performing a "Learn-Known-Good" function. During Learn-Known-Good, the tester determines the order of the wire list. Tester defined wire list orders are acceptable for test applications, but for assembly applications, the build order is important and therefore requires that the wire list be entered through a keyboard.
The second part of the program is the cross reference or user label list. The wire list specifies the wiring relationship between the ends of the wires and the pins of the harness connectors. The cross reference list is the wiring relationship of the interconnect. It specifies the placement between the pins of the mating connectors and the test points of the tester. This part of the program has to be entered through a keyboard and is programmed after the interconnect is built. Without the cross reference list, the tester would display test results relative to test points and not to actual wire harness locations.
There is need for improvement or improvements in apparatus and techniques used for testing wire harnesses, allowing more rapid, accurate and reliable testing, and reduced test apparatus cost.